AC N - Auto Correlation - Normalized ||

PURPOSE

Computes the normalized auto-correlation function of image/volume by using the Fourier transform relationship.   Example.

SEE ALSO

AC	[Auto Correlation ||]
AC MS	[Auto Correlation - Masked and normalized ||]
CC	[Cross Correlation ||]
CC N	[Cross Correlation - Normalized ||]
CN	[Convolution ||]
CN N	[Convolution - Normalized ||]
FT	[Fourier Transform ||]

USAGE

.OPERATION: AC N

.INPUT FILE: PIC001
[Enter the name of the picture to be auto-correlated.]

.OUTPUT FILE: ACF001
[Enter name of the file which will contain the auto-correlation coefficients.]

NOTES

1. On completion of this operation, the output file will contain the auto-correlation function. The origin is at: (NX/2 + 1, NY/2 + 1, NZ/2 + 1).

2. The input data must be real.

3. If the data cannot fit into the memory, use the 'FT' and 'SQ' commands to calculate the ACF:
      FT
      INPUT
      FOUR
   
      SQ
      FOUR
      MODFT
   
      FT
      MODFT
      ACF
   
   WARNING: The orgin of the ACF calculated in this way is in (1,1,1).

SUBROUTINES

NORM3, FMRS_2, FMRS_2R, FFTMCF, FMRS_1, FMRS_3, FMRS_3R, ACRS_2, ACRS_3

CALLER

CORR1